scholarly journals Enhancing the effective critical current density in a Nb superconducting thin film by cooling in an inhomogeneous magnetic field

2021 ◽  
Vol 119 (2) ◽  
pp. 022602
Author(s):  
D. A. D. Chaves ◽  
I. M. de Araújo ◽  
D. Carmo ◽  
F. Colauto ◽  
A. A. M. de Oliveira ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Inhomogeneous Magnetic Field ◽  
Superconducting Thin Film

Estimation of Local Current Transport Properties in Thin Film Superconductor Based on Scanning Hall-probe Microscopy

2012 ◽  
Vol 1434 ◽  
Author(s):  
Kohei Higashikawa ◽  
Kei Shiohara ◽  
Masayoshi Inoue ◽  
Takanobu Kiss ◽  
Masateru Yoshizumi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Critical Current Density ◽  
Electric Field ◽  
Critical Current ◽  
Current Density ◽  
Limiting Factors ◽  
Hall Probe ◽  
Scanning Hall Probe Microscopy ◽  
Field Criterion

ABSTRACTTo enhance a global critical current in a superconductor, it is indispensable to understand current limiting factors and their influence on such a critical current. From this point of view, we have investigated in-plane distribution of local critical current density and its electric field criterion in a thin-film superconductor by using scanning-Hall probe microscopy. In a remanent state, after the application of sufficiently high magnetic field to a sample, current flows at critical current density according to the critical state model. Such distribution of current density was estimated from that of measured magnetic field using the Biot-Savart law. Furthermore, the corresponding electric field criterion was evaluated from the relaxation of such remanent magnetic field by considering Faraday’s law. This means that we could estimate in-plane distribution of local critical current density as a function of electric field criterion in a nondestructive manner. This characterization method would be very helpful for finding current limiting factors in a thin-film superconductor and their influence on its global current density versus electric field properties which would usually be obtained by four-probe method.

Angular Dependence of Magnetic Field on Critical Current Density in Tl2Ba2Ca2Cu3Ox Thin Film

1991 ◽  
pp. 555-558
Author(s):  
Toshihide Nabatame ◽  
Yukio Saito ◽  
Katsuzo Aihara ◽  
Tomoichi Kamo ◽  
Shin-Pei Matsuda
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Critical Current Density ◽  
Critical Current ◽  
Angular Dependence ◽  
Current Density

scholarly journals Flux avalanche in a superconducting film with non-uniform critical current density

2016 ◽  
Vol 472 (2194) ◽  
pp. 20160469 ◽  
Author(s):  
Yurong Lu ◽  
Ze Jing ◽  
Huadong Yong ◽  
Youhe Zhou
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Environmental Temperature ◽  
Dendritic Structure ◽  
Heat Diffusion ◽  
Superconducting Film ◽  
Superconducting Thin Film ◽  
Heat Diffusion Equation

The flux avalanche in type-II superconducting thin film is numerically simulated in this paper. We mainly consider the effect of non-uniform critical current density on the thermomagnetic stability. The nonlinear electromagnetic constitutive relation of the superconductor is adopted. Then, Maxwell's equations and heat diffusion equation are numerically solved by the fast Fourier transform technique. We find that the non-uniform critical current density can remarkably affect the behaviour of the flux avalanche. The external magnetic field ramp rate and the environmental temperature have been taken into account. The results are compared with a film with uniform critical current density. The flux avalanche first appears at the interface where the critical current density is discontinuous. Under the same environmental temperature or magnetic field, the flux avalanche occurs more easily for the film with the non-uniform critical current density. The avalanche structure is a finger-like pattern rather than a dendritic structure at low environmental temperatures.

Characteristics of critical current density and weak links in an YBa2Cu3O7−δ superconducting thin film

1990 ◽  
Vol 167 (1-2) ◽  
pp. 75-78 ◽  
Author(s):  
H.H. Wen ◽  
J. Fang ◽  
J.H. Lu ◽  
X.W. Cao ◽  
J.Z. Shi ◽  
...  
Keyword(s):  
Thin Film ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Weak Links ◽  
Superconducting Thin Film

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

STUDY OF THE TEXTURING IN BSCCO-AG TAPES THROUGH MAGNETIC MEASUREMENTS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3159-3164
Author(s):  
C. FERDEGHINI ◽  
M. R. CIMBERLE ◽  
G. GRASSO ◽  
P. GUASCONI ◽  
A. MALAGOLI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Measurements ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Longitudinal Direction ◽  
Magnetic Method ◽  
Superconducting Compounds

We have developed a method that allows, by a simple set of magnetic measurements, to study the texturing of the grains inside a BSCCO-Ag tape. Because the texture is anisotropic we define the angle ϑ L that identifies the mean grain misalignment angle with respect to the tape surface in longitudinal direction (i.e. rolling direction) and the angle ϑ T in transverse direction. The technique is based on the assumption that, because of the very high anisotropy of the critical current density in BSCCO superconducting compounds, the magnetic moment is essentially generated by the current circulating in the a-b planes of the BSCCO grains. The different magnetisation cycles, measured when the orientation of the magnetic field with respect to the tape surface is changed, depend only on the grain orientation inside the tape, which determines the effective magnetic field component normal to the a-b planes of the grains. Here we present the texture evolution of the BSCCO grains inside silver sheated multifilamentary tape starting from the initial steps of the mechanical deformation up to the final heating stage. The results obtained from the magnetic method are compared with those obtained with other methods, i.e. X-ray diffraction and critical current density anisotropy. Also results obtained on samples prepared in different way will be presented.

The Critical Current Density and the Curvature of the Magnetic Field in Epitaxial YBaCuO Films

1992 ◽  
Vol 170 (2) ◽  
pp. 549-562 ◽  
Author(s):  
D. Glatzer ◽  
A. Forkl ◽  
H. Theuss ◽  
H. U. Habermeier ◽  
H. Kronmüller
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
The Magnetic Field
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